Compressed-air motor.



Nu. 868,441. PATENTED OCT". 15, 1907. G. D. JENKINS. COMPRESSED AIR MOTQR.

APPLICATION FILED MAY 6. 1907.

NORRIS PETERS INCH LIIHG "nsm-ucron D C riicating by the passage 24 with a port 25 in the bottonr UNITED STATES PATENT OFFICE.

CHARLES D. JENKINS, OF BOSTON, MASSACHUSETTS COMPRESSED-AIR- MOTOR.

ltd-sad sm.

Specification of Letters Patent.

ApplioationfiledMayG,1907. SerialNo- 372,117.,

To (ZZZ whom it may concern: I Be it known that I, CHARLES D. JENKINS, a citizen of the United States, residing in Boston, in the county oi Simon; and State of Massachusetts, have invented an Improvement in Compressed-Air Motors, of which the following description, in connection with the accompanying drawings, is a specification, like letters on the drawings representing like parts.

i This invention relates to motors to be operated by compressed-air and has for itsobject the production of a motor in which heat is applied to the compressed-air at the point it is to act upon the piston thereby greatly increasing the efiiciency thereof.

a It consists in certain novel featm'es of construction and arrangement of parts which will be understood "readily'by reference to the description of the drawings and to the claims to be hereinafter given.

The drawings represent a diagrammatic view of the various features which constitute this invention.

In the drawing 10 is a suitabletank or reservoir for the-storage of compressed-air under suitable pressure, said tank being connected by a pipe 11 and branch papes 12 to the cylinder casting 13, which is provided with a plurality of cylinders 14. In each cylinder is mounted a piston 15 connected by a piston rod 16 to a crank 17 on the shaft 18 mounted in bearings 19 and provided with a driving wheel 20, from which power may be transmitted to any desired point.

Eln the cylinder casting 13 are passages 21 connecting wllth the branch pipes 12 at one end and with the ports 22 at the other end communicating with the cylinders 14: I Adjacent to the port 22 is anoth r port 23 commuof the cylinder 14. Each piston 15 is provided with a passage 26 so located that when the piston is at the extreme inner end of its movement, it will communicate with both the ports 22 and 23 and permit the passage of compressed-air through the pipes 12, passages 2l'and 24 and ports 25 to the cylinder 14 back of the piston 15.

The piston 15 serves to close the ports 22, 23 and thereby prevent the passage of the compressed-air to the cylinder except when the piston is in the proper position to be acted upon by the expansion of the compressedair. A check valve 14 prevents the 'exit from the cylirider of the compressed air admitted thereto during the expansion thereof. An exhaust port 27 also communicates with each cylinder 14 and connects the same by passages 28 and pipes 29 and 30 with a coil 31 located in a tank 32, the opposite end of said coil being connected by a pipe 33:,to a pump 34 arranged to pump the exhaust air through the pipe 35 into the main reservoir, 3. check valve 36 preventing the return thereof.

Each piston is provided upon its inner end with an electric coil 37 and two contact points 38, which, when the piston is at the inner end or chamber-forming portion of its stroke, make an electric connection with the circuit 39 in which is a battery or other-generator ofelectricity, 40. When'the circuit is made, by'the movement of the piston 15, a currentoi electricity passes through the coil 37 or a similar heating device and causes an intense heat, which, acting upon the compressed-air being at this time admitted to the cylinder, greatly expands the, same and increases its efficiency. This forms a very important feature of the invention as it provides a very convenient means for increasing the powerof a compressed-air motor without the necessity of increasing the pressure in the storage tank. The tank 32 is used to cool the exhaust air passing from the cylinders 14, it being provided with an inlet pipe '41 and outlet pipe 42, which permits water I or other cooling [liquid to be admitted as desired and by contact with the coil 31 to cool the air passing-through the same before it is pumped back intQlhe reservoir 10.

The operation of the invention isas follows:The tank 10 is supplied with compressed-air from any convenient source and under any desired pressure. When it is desired to start the engine, the valve 43 is opened and the compressed-air is allowed to pass through the pipes 12 to the ports 21. By turning the driving wheel by hand the air is admitted to the cylinders 14 and is then expanded by the heat in coils37, so that the pistons will be driven to the opposite ends of their strokes. As soon as each piston begins to move, the heat is shut off and remains shut off until the piston again reaches the bottom of the cylinder when'the operation isrepeated. The cranks 17 are placed at equal distances about-the shaft 18 so that the motor will be perfectly balanced. As soon as the motor has made a few revolutions by the aid of the operator it will continue to operate'until the valve 43 is again closed. The exhaust Patented Oct. 15,1907. l

from the engine is thoroughly cooled in the tank 32,

thereby lowering the pressure thereof before being pumped back into the storage reservoir 10.

Claims.

1. The combination with a source of air under pressure, of in air engine comprising a cylinder and a piston reciprocating in said cylinder and cooperating therewith to form a substantially sniall chamber when the piston is at the end of its stroke in one direction, means'to admit compressed-air into said chamber, an electrioconductor located in said chamber when the piston is at the end of the stroke on which said chamber'is formed and capable of being highlyheated, an electric circuit in which said con' ductor is included when the piston is at the end of its chamber-forming stroke, and a circuit contrdller for said circuit operated to close the same and highly heat the conductor when the piston is at or near the end of its'chnmbar-forming stroke to thereby expand the compresed-air an electric conductor movable with said piston, an'electric circuit having terminals extended within said cylinder and cooperating with said electricconductor to include thelatter in a closed circuit and thereby highly heat the 16 conductor when the pis ton'is at the end of its'stroke in one direction, substantially as described.

In testimony whereof, I'have signed my name to this specification in the presence of two subscribing witnesses.

' CHARLES D. JENKINS.

- 1 Witnesses .TAs. H. CHURCHILL, J. MURPHY.' 

